Organic light-emitting diode (OLED) devices initially found acceptance as relatively small display devices. Typically OLED devices have a hole-transporting layer and electron-transporting layer disposed on either side of a organic light-emitting layer. Spaced electrodes cause current to pass through the OLED, and the combination of holes and electrons in the organic light-emitting layer produces light. These OLED devices typically have either a passive-matrix or active-matrix drive format. Flat-panel devices, such as television displays, presentation displays, or light-emitting panels, are becoming more popular. Flat-panel OLED devices offer a number of advantages for these applications. However, there are problems associated with flat-panel OLED devices. To reduce weight, OLED devices typically use a thin, deformable substrate that can bend, fracture, or break, thereby distorting the light output. Another difficulty is that if the substrate is thin, the OLED can produce enough heat to distort the substrate.
Various methods have been used to provide support for OLED devices. Guenther, in U.S. Pat. No. 6,660,547, discloses a support rim for electroluminescent devices. Heimgartner, in U.S. Pat. No. 6,688,933, teaches the use of a structural frame for electroluminescent devices. Guenther et al., in U.S. Pat. No. 7,026,758, disclose a stiff reinforcement lid for an electroluminescent device, wherein the lid serves to support the device. In none of these cases, however, is any provision made for removing heat.
Kikuchi et al., in U.S. Pat. No. 7,063,902, teach an OLED that has been encapsulated with a filler layer that is heat-conductive. However, there is no indication of how to provide such a heat-conductive layer with support. In JP 10-275681, there is shown a protecting layer with a metal filler and carbon powder to provide high heat conductance.
It is thus a problem to be solved to provide both structural support and heat dissipation to an electroluminescent device.